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We calculate corrections to the power spectrum predictions of weak lensing by large scale structure due to higher order effects in the gravitational potential. Using a perturbative approach to third order in transverse displacements, we…

Astrophysics · Physics 2011-05-12 Asantha Cooray , Wayne Hu

We use statistical inference theory to explore the constraints from future galaxy weak lensing (cosmic shear) surveys combined with the current CMB constraints on cosmological parameters, focusing particularly on the running of the spectral…

Astrophysics · Physics 2009-11-10 Mustapha Ishak , Christopher M. Hirata , Patrick McDonald , Uros Seljak

We present a weak lensing analysis of the 3 GHz VLA radio survey of the COSMOS field, which we correlate with overlapping HST-ACS optical observations using both intrinsic galaxy shape and cosmic shear correlation statistics. After…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-27 Tom Hillier , Michael L. Brown , Ian Harrison , Lee Whittaker

We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-moments of the cosmic shear field, estimated from about 450,000 galaxies with average redshift <z> ~ 1.3. We measure two- and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Elisabetta Semboloni , Tim Schrabback , Ludovic van Waerbeke , Sanaz Vafaei , Jan Hartlap , Stefan Hilbert

Weak gravitational lensing provides a unique method to directly map the dark matter in the universe and measure cosmological parameters. Current weak lensing surveys are limited by the atmospheric seeing from the ground and by the small…

We present the first measurement of weak lensing by large-scale structure on 1-4 degree scales based on the FIRST Radio Survey, a quarter-sky, 20-cm survey produced with the NRAO Very Large Array (VLA). The large angular scales provide an…

Astrophysics · Physics 2009-11-10 Tzu-Ching Chang , Alexandre Refregier , David J. Helfand

Different options can be used in order to measure the shear from observations in the context of weak lensing. Here we introduce new methods where the isotropy assumption for the distribution of the source galaxies is implemented directly on…

Astrophysics · Physics 2008-02-03 Marco Lombardi , Giuseppe Bertin

Weak lensing provides a direct measure of the distribution of mass in the universe, and is therefore a uniquely powerful probe of dark matter. Weak lensing can also be used to measure the twin phenomenon of dark energy, via its effect upon…

Astrophysics · Physics 2007-05-23 Richard Massey , Alexandre Refregier , Jason Rhodes

We revisit the estimation of higher order corrections to the angular power spectra of weak gravitational lensing. Extending a previous calculation of Cooray and Hu, we find two additional terms to the fourth order in potential perturbations…

Astrophysics · Physics 2011-05-12 Charles Shapiro , Asantha Cooray

A stochastic gravitational wave background (SGWB) will affect the CMB anisotropies via weak lensing. Unlike weak lensing due to large scale structure which only deflects photon trajectories, a SGWB has an additional effect of rotating the…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Shabbir Shaikh , Suvodip Mukherjee , Aditya Rotti , Tarun Souradeep

We demonstrate that the aperture mass as a measure for cosmic shear closely approximates (to better than ~5%) the scaled and shifted power spectrum of the projected mass density. This cosmological weak-lensing information can thus be used…

Astrophysics · Physics 2007-05-23 Matthias Bartelmann , Peter Schneider

The Bipolar Spherical Harmonics (BipoSH) form a natural basis to study the CMB two point correlation function in a non-statistically isotropic (non-SI) universe. The coefficients of expansion in this basis are a generalisation of the well…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-30 Moumita Aich , Aditya Rotti , Tarun Souradeep

Now that weak lensing signals on the order of a percent are actively being searched for (cosmic shear, galaxy-galaxy lensing, large radii in clusters...) it is important to investigate how accurately weak shears can be determined. Many…

Astrophysics · Physics 2016-08-30 K. Kuijken

Weak gravitational lensing is one of the key probes of the cosmological model, dark energy, and dark matter, providing insight into both the cosmic expansion history and large scale structure growth history. Taking into account a broad…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-12 Sudeep Das , Roland de Putter , Eric V. Linder , Reiko Nakajima

We present current and future constraints on equations of state for dark sector perturbations. The equations of state considered are those corresponding to a generalized scalar field model and time-diffeomorphism invariant $L(g)$ theories…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-29 Richard A. Battye , Adam Moss , Jonathan A. Pearson

The standard weak lensing formalism assumes that the lensing map relating the observed image of a source to its intrinsic shape depends only on the deflection angle. We show that this description is incomplete beyond linear perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-26 Matteo Magi , Francesca Lepori , Julian Adamek

We develop a pseudo power spectrum technique for measuring the lensing power spectrum from weak lensing surveys in both the full sky and flat sky limits. The power spectrum approaches have a number of advantages over the traditional…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-06 Chiaki Hikage , Masahiro Takada , Takashi Hamana , David Spergel

Galaxy-galaxy weak lensing provides a powerful means of measuring the average matter distribution around lens galaxies -- i.e., the galaxy bias relation. Properly accounting for the spin-2 nature of weak lensing distortions, we develop a…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Taisei Terawaki , Masahiro Takada , Takanori Taniguchi

We investigate weak lensing effect on cosmic microwave background (CMB) in the presence of dipole anisotropy. The approach of flat-sky approximation is considered. We determine the functions $\sigma_0^2$ and $\sigma_2^2$ that appear in…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-24 Abhineet Agarwal , Naveen K. Singh , Pankaj Jain , Prabhakar Tiwari

Weak gravitational lensing on a cosmological scales can provide strong constraints both on the nature of dark matter and the dark energy equation of state. Most current weak lensing studies are restricted to (two-dimensional) projections,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Alan Heavens , Peter Coles